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Shake at idle (or 2.5 trouble part2


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I am glad there are forums on the net because the dealer says that there really isnt anything that they can do and I already spent $1600+ working on it and am getting frustrated!

I have a 2.5 auto '97 Suba Legacy outback with 110,000 mi. This should be just nicely broken in for a Suby. It vibrates at idle.It does it most of the time. It staarted about 4000 mi ago while returning from vacation and pulling a 1500 lb trailer. The left 1/2 axle also gave out on that trip but it made it home and I replaced it.Weather conditions don't matter. Sometimes it only shakes the steering wheel. Sometimes the door panels vibrate loudly and the whole car vibrates. It only happens in gear. If I go to neutral it stops vibrating. It is associated with a stumble at low RPM that developed around the same time.Both were intermittent. There was no check engine light.I took it to the dealer and they changed the head gaskets (CO1 in the radiator.) They did a fuel system cleaning for $69.They also did the timing belts while they were in there. They said it was much improved. No change. I had the feeling they had been here before. I made another appointment and they cleaned out some other parts of the fuel system. They checked all the hoses and everything was fine now. I was told that if there was still a vibration then my only recourse was to replace both 1/2 axles with genuine Suby parts. That was what the factory manual said. They also admitted that they had never ordered a genuine Suby 1/2 axle because of the price and that they used rebuilt ones there themselves but if I didnt use genuine ones they could not be sure it would go away. Price $800 if I wanted. I got the other one replaced with a rebuilt one. It still shakes. They really don't want anything to do with it anymore. Any suggestions? Is there something they aren't telling me?

Kahoona

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My 98 O/B WGN does the same thing....(it's got 205,000kms).

When I'm stopped at a light in Drive with the brake on, it shudders. If I pop it into neutral it runs smooth. I tried something the other day...I parked on a hill which was steep enough to stop the car from moving forward OR backward while in drive with my foot OFF the brake...it still shuddered.

Around the same time it started shuddering, it also started shifting with a thunk from 1st to 2nd,(mostly while accelerating slowly. I drained the tranny oil and replaced it,(it hadn't been drained for over a year...60K+), and it didn't make any difference.

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I also have a 97 OB. 402,000 km now. Automatic transmission.

 

I've never really had any idle issues, but I have had the low rpm stumble a couple of times. The first time, about 3 or 4 years ago, it was from a carbon build up. A MotorVac cleaning resolved that. Then it happened a year back. My usual tricks (gas cleaner, a couple of tanks of premium) did not get rid of it. I started suspecting the O2 sensor. I never had any codes. They said the sensor was ok, just acting a bit "slow". I eventually decided to change it. The low rpm stumble improved dramatically immediately. After several weeks, it was totally gone.

 

So... I'm saying that you might have an issue with a weak O2 sensor causing the engine to run rich. And these cars run rich to begin with (fuel maps are that way it seems).

 

One other thing. When I had my engine changed just over 2 years ago, I opted to put in the liquid filled engine mounts that the 2000+ Legacys use. This might be partly why I don't get a shake developing. But, as I mentioned above, I didn't have a shake issue even the first time it happened.

 

I've read of issues with half shafts, but I can't really comment there. I fail to understand how they would cause a shake when you are not moving. Well, I can think of a couple of things, but it just seems very strange to me.

 

When the shake is happening, is it only at that particular rpm? That is, if you touch the gas to increase the rpm by (say) 100, does the shake get worse, or go away? Is it a case of a resonance frequency being excited?

 

Commuter

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The fact that it does it while stopped leads me to believe it's the transmission,(and also that it's OK when in neutral). I haven't tried bringing up the revs while stopped however. Maybe revving 100 rpm's or so more might help.

 

Tell me more about your engine change. Why...who..and how much $$.

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The difference between being in D and either N or P is simly that the drive pin is engaged (when in D) and now you are spinning your torque converter. The trans is not spinnnig until you let off the brakes and the Torque converter which acts similar to a clutch now has less resistance allowing it to make your car roll. Sounds like your dealer's mechanics need to go back to kindergarden mechanic school. If it idles fine, revs fine, and tacks out fine and smooth so long as the car is not in gear then you have a drive train problem. I would call around and price out having your TQ converter replaced. My subie only has 105k right now and the trans (auto) shifts harder then I would like, but then I hear all the autos do that.

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At 72,000 miles my 2000 2.5L idles so smooth most of the time I look at the tachometer to make sure it's idling. Assumiming you have a good tuneup I wonder if the valve clearence correct. On 2.5L engines the check/adjust interval is 60,000 or 105,000 miles depending on DOHC or SOHC.

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I have a 2.5 auto '97 Suba Legacy outback with 110,000 mi. This should be just nicely broken in for a Suby. It vibrates at idle.It does it most of the time. It staarted about 4000 mi ago while returning from vacation and pulling a 1500 lb trailer. The left 1/2 axle also gave out on that trip but it made it home and I replaced it.

So this started after you replaced the 1/2 axle?

If so it still may be the axle

What can happen is when it is "Remanufactured" Inner joint is made to tight and when under torque it will bind and cause a vibration while taking off,

The vibration at idle can be caused by the inner joint binding as well, when the car is in drive there is torque in the forward direction, if the inner joint can not move in and out with the movement of the engine/ transmission, it tens to make things solid and transmit the vibration from the engine/ transmission thought the axle to the body of the car

Question is how much more money do you want to throw at this and it may rectify itself as the axle wears in !

SEA#3

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My 98 O/B WGN does the same thing....(it's got 205,000kms).

When I'm stopped at a light in Drive with the brake on, it shudders. If I pop it into neutral it runs smooth. I tried something the other day...I parked on a hill which was steep enough to stop the car from moving forward OR backward while in drive with my foot OFF the brake...it still shuddered.

Around the same time it started shuddering, it also started shifting with a thunk from 1st to 2nd,(mostly while accelerating slowly. I drained the tranny oil and replaced it,(it hadn't been drained for over a year...60K+), and it didn't make any difference.

 

Hey CHIP...my car (99 OBW, 47,000 mi) does the exact thing you mentioned above!! have you heard what this might be yet? I just got this car and I'm considering getting an extended warranty ever since I noticed these little episodes.

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If you have not, change your trany fluid. I would spend the extra $30 and replace it with redline synthetic (or what ever flavor you like). It's obviously coming from the trans. I've seen engines with bearings that go out and they will shake like hell, in or out of gear.

After that trip pulling that trailer you probably burnt the hell out of your trany fluid. If it's never been changed it's way past due anyhow.

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  • 2 weeks later...
Hey CHIP...my car (99 OBW, 47,000 mi) does the exact thing you mentioned above!! have you heard what this might be yet? I just got this car and I'm considering getting an extended warranty ever since I noticed these little episodes.

 

I haven't found anything out yet and I'm trying to stay away from the dealer. Unless it gets really bad I'm not going to worry about it.

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  • 2 weeks later...
I haven't found anything out yet and I'm trying to stay away from the dealer. Unless it gets really bad I'm not going to worry about it.

 

anyone find out anything definitive yet? my '96 legacy 2.2l has the same symptoms -- shake at idle in gear, but pop it into N and the shake goes away.

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I think it's just inherent in the cars. Both our 2.2L in the '95 and the 2.5L in the '00 shake mildly in drive and idle butter smooth in park or neutral.

 

I've always assumed it was interaction between the engine and the torque converter. Since both cars run fine, have had regular tranny services and are at 150,000+ ('00) and 125,000+ ('95), I just slip it in neutral when at long stops and don't worry about it.

 

BTW, the flat four in my airplane shakes at idle too! ;-)

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I think it's just inherent in the cars. Both our 2.2L in the '95 and the 2.5L in the '00 shake mildly in drive and idle butter smooth in park or neutral.

 

I've always assumed it was interaction between the engine and the torque converter. Since both cars run fine, have had regular tranny services and are at 150,000+ ('00) and 125,000+ ('95), I just slip it in neutral when at long stops and don't worry about it.

 

BTW, the flat four in my airplane shakes at idle too! ;-)

yeah, i think some of the shake is inherent, but it's gotten way worse over the lifetime of the car (ie, the glovebox door rattles loudly, as does the steering column.)

 

I can't help but wonder what exactly is going on...

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  • 1 month later...

Lets add to the confusion. I have a '98 OBW that just blew a head gasket.. and it didn't shake at idle. I just dropped a '99 yard engine with ~60k miles in it. Engine runs good but shakes the car to He.. when I'm at a stop.

 

I actually think there is a strong chance it is the torque converter. When I pulled the old engine I made a big mistake, I yanked it with the torque converter still bolted on. The converter came out.. and so did the shaft that goes into it. Everthing pushed back in OK on the re-install, but now I have the shakes!

 

Otherwise all I have left to try is: o2 sensors, injectors, and possibly a valve adjustment...

 

Thoughts anyone?

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I'm no expert, but here's what I've seen in the recent past...

 

My 98 Legacy Outback w/ 5sp manual tranny idled rough when I replaced the timing belt. Turned out I was one tooth off on the timing... when fixed, ran great. When rough, I could feel the exhaust coming out of the muffler was puttering a bit.

 

My girlfriend's 92? Toyota Camry recently blew a fuel injector. It would run, but idled rough. We replaced tons of stuff before we finally had a good shop diagnose it as the injector. Her exhaust puttered as well.

 

anyway, good luck.

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  • 2 months later...
anyone find out anything definitive yet? my '96 legacy 2.2l has the same symptoms -- shake at idle in gear, but pop it into N and the shake goes away.

My 98 Leg GT has a similar issue - 4EAT - in P or N the car is fine. In D the car idles a little rough, but nothing major. It does sound kind of "puttery" but I attribute that to the restrictive (and well used) exhaust system (165,000 miles on this engine).

 

I get vibration through the cabin of the car (feels like driveline) on acceleration from 1500 - 2500rpm until the gearing switches up and the car cruises. Higher rpms are no problem at all.

 

From reading the posts above, I am leaning towards the torque convertor, but on a car with this many miles I am planning to replace the engine mounts and transmission mounts (with STi components if available).

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